Late period but not pregnant....

Maya🌸🦄🎀

Okay so I'm very confused and worried because my period is 44 days late but I'm not pregnant I've taken 6 different test and they all show negative. Is it even possible for some many test to be wrong? I honestly don't believe I am but I have been having some problems with my weight gain. However people tell me that my period being late can be for many different reasons. Please help any advise will be greatly appreciated !